ABSTRACT
H6P2W18O62 is used as an efficient catalyst for the synthesis of novel N-substituted sulfonyl maleimides (1H-Pyrrole-2,5-diones) via the condensation of sulfonamide and maleic anhydride derivatives. The Dawson heteropolyacid was used with a catalytic amount of 2 mmol% in acetonitrile at reflux. The reuse of H6P2W18O62 as heterogeneous catalyst several times without decrease in their activity, short reaction times, easy isolation of desired products with good to excellent yields shows the advantages of this novel methodology.